Pulmonary congestion (pulmonary edema) is the accumulation of fluid in the pulmonary tissues and air spaces in the lungs of a patient due to changes in hydrostatic forces in the capillaries. Pulmonary edema may be caused by increased pulmonary capillary hydrostatic pressure. A patient with pulmonary edema may experience shortness of breath and difficulty breathing.
PESP is a pacing therapy for improving cardiac function that used paired- or coupled pacing of a cardiac chamber. PESP is a property of cardiac cells whereby a pair of closely-spaced depolarizations of a heart chamber results in subsequent contractions that are of an increased magnitude.
PESP may be employed by supplying an “extra” pacing stimulus, delivered shortly after an intrinsic (or paced) depolarization event, which causes a second depolarization without a corresponding mechanical contraction. The time interval between the initial depolarization event and the extra pacing stimulus is called the extra stimulus interval, or ESI. In general, the shorter the ESI, the greater the magnitude of the PESP effect.